#include <stdio.h>

#define M 3
#define N 5

void double_val(int m, int n, double source[m][n]);

void show(int m, int n, double array[m][n]);

int main() {
    double source[M][N] = {
            {1.0,2.0,3.0,4.0,5.0},
            {1.1,2.2,3.3,4.4,5.5},
            {11.0,12.0,13.0,14.0,15.0},
    };
    show(M, N, source);
    double_val(M, N, source);
    printf("\n");
    show(M, N, source);
    return 1;
}

void double_val(int m, int n, double source[m][n]){
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < n; ++j) {
            source[i][j] *= 2;
        }
    }
}

void show(int m, int n, double array[m][n]) {
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < n; ++j) {
            printf("%.2f\t", array[i][j]);
        }
        printf("\n");
    }
}
